/*
 * Copyright (c) 1999-2002, 2018 Proofpoint, Inc. and its suppliers.
 *	All rights reserved.
 *
 * By using this file, you agree to the terms and conditions set
 * forth in the LICENSE file which can be found at the top level of
 * the sendmail distribution.
 *
 *	$Id: smdb.h,v 8.42 2013-11-22 20:51:28 ca Exp $
 *
 */

#ifndef _SMDB_H_
# define _SMDB_H_

# include <sys/types.h>
# include <sys/stat.h>
# include <sm/gen.h>
# include <sm/errstring.h>

# if NDBM
#  include <ndbm.h>
# endif

# if NEWDB
#  include "sm/bdb.h"
# endif

/*
**  Some size constants
*/

#define SMDB_MAX_USER_NAME_LEN	1024

/*
**  This file defines the abstraction for database lookups. It is pretty
**  much a copy of the db2 interface with the exception that every function
**  returns 0 on success and non-zero on failure. The non-zero return code
**  is meaningful.
**
**  I'm going to put the function comments in this file since the interface
**  MUST be the same for all inheritors of this interface.
*/

typedef struct database_struct SMDB_DATABASE;
typedef struct cursor_struct SMDB_CURSOR;
typedef struct entry_struct SMDB_DBENT;

/*
**  DB_CLOSE_FUNC -- close the database
**
**	Parameters:
**		db -- The database to close.
**
**	Returns:
**		0 - Success, otherwise errno.
**
*/

typedef int (*db_close_func) __P((SMDB_DATABASE *db));

/*
**  DB_DEL_FUNC -- removes a key and data pair from the database
**
**	Parameters:
**		db -- The database to close.
**		key -- The key to remove.
**		flags -- delete options. There are currently no defined
**			 flags for delete.
**
**	Returns:
**		0 - Success, otherwise errno.
**
*/

typedef int (*db_del_func) __P((SMDB_DATABASE *db,
			   SMDB_DBENT *key, unsigned int flags));

/*
**  DB_FD_FUNC -- Returns a pointer to a file used for the database.
**
**	Parameters:
**		db -- The database to close.
**		fd -- A pointer to store the returned fd in.
**
**	Returns:
**		0 - Success, otherwise errno.
**
*/

typedef int (*db_fd_func) __P((SMDB_DATABASE *db, int* fd));

/*
**  DB_GET_FUNC -- Gets the data associated with a key.
**
**	Parameters:
**		db -- The database to close.
**		key -- The key to access.
**		data -- A place to store the returned data.
**		flags -- get options. There are currently no defined
**			 flags for get.
**
**	Returns:
**		0 - Success, otherwise errno.
**
*/

typedef int (*db_get_func) __P((SMDB_DATABASE *db,
			   SMDB_DBENT *key,
			   SMDB_DBENT *data, unsigned int flags));

/*
**  DB_PUT_FUNC -- Sets some data according to the key.
**
**	Parameters:
**		db -- The database to close.
**		key -- The key to use.
**		data -- The data to store.
**		flags -- put options:
**			SMDBF_NO_OVERWRITE - Return an error if key alread
**					     exists.
**
**	Returns:
**		0 - Success, otherwise errno.
**
*/

typedef int (*db_put_func) __P((SMDB_DATABASE *db,
			   SMDB_DBENT *key,
			   SMDB_DBENT *data, unsigned int flags));

/*
**  DB_SYNC_FUNC -- Flush any cached information to disk.
**
**	Parameters:
**		db -- The database to sync.
**		flags -- sync options:
**
**	Returns:
**		0 - Success, otherwise errno.
**
*/

typedef int (*db_sync_func) __P((SMDB_DATABASE *db, unsigned int flags));

/*
**  DB_SET_OWNER_FUNC -- Set the owner and group of the database files.
**
**	Parameters:
**		db -- The database to set.
**		uid -- The UID for the new owner (-1 for no change)
**		gid -- The GID for the new owner (-1 for no change)
**
**	Returns:
**		0 - Success, otherwise errno.
**
*/

typedef int (*db_set_owner_func) __P((SMDB_DATABASE *db, uid_t uid, gid_t gid));

/*
**  DB_CURSOR -- Obtain a cursor for sequential access
**
**	Parameters:
**		db -- The database to use.
**		cursor -- The address of a cursor pointer.
**		flags -- sync options:
**
**	Returns:
**		0 - Success, otherwise errno.
**
*/

typedef int (*db_cursor_func) __P((SMDB_DATABASE *db,
			      SMDB_CURSOR **cursor, unsigned int flags));

typedef int (*db_lockfd_func) __P((SMDB_DATABASE *db));

struct database_struct
{
	db_close_func		smdb_close;
	db_del_func		smdb_del;
	db_fd_func		smdb_fd;
	db_get_func		smdb_get;
	db_put_func		smdb_put;
	db_sync_func		smdb_sync;
	db_set_owner_func	smdb_set_owner;
	db_cursor_func		smdb_cursor;
	db_lockfd_func		smdb_lockfd;
	void			*smdb_impl;
};

/*
**  DB_CURSOR_CLOSE -- Close a cursor
**
**	Parameters:
**		cursor -- The cursor to close.
**
**	Returns:
**		0 - Success, otherwise errno.
**
*/

typedef int (*db_cursor_close_func) __P((SMDB_CURSOR *cursor));

/*
**  DB_CURSOR_DEL -- Delete the key/value pair of this cursor
**
**	Parameters:
**		cursor -- The cursor.
**		flags -- flags
**
**	Returns:
**		0 - Success, otherwise errno.
**
*/

typedef int (*db_cursor_del_func) __P((SMDB_CURSOR *cursor,
					unsigned int flags));

/*
**  DB_CURSOR_GET -- Get the key/value of this cursor.
**
**	Parameters:
**		cursor -- The cursor.
**		key -- The current key.
**		value -- The current value
**		flags -- flags
**
**	Returns:
**		0 - Success, otherwise errno.
**		SMDBE_LAST_ENTRY - This is a success condition that
**				   gets returned when the end of the
**				   database is hit.
**
*/

typedef int (*db_cursor_get_func) __P((SMDB_CURSOR *cursor,
				  SMDB_DBENT *key,
				  SMDB_DBENT *data,
				  unsigned int flags));

/*
**  Flags for DB_CURSOR_GET
*/

#define SMDB_CURSOR_GET_FIRST	0	/* NOT USED by any application */
#define SMDB_CURSOR_GET_LAST	1	/* NOT USED by any application */
#define SMDB_CURSOR_GET_NEXT	2
#define SMDB_CURSOR_GET_RANGE	3	/* NOT USED by any application */

/*
**  DB_CURSOR_PUT -- Put the key/value at this cursor.
**
**	Parameters:
**		cursor -- The cursor.
**		key -- The current key.
**		value -- The current value
**		flags -- flags
**
**	Returns:
**		0 - Success, otherwise errno.
**
*/

typedef int (*db_cursor_put_func) __P((SMDB_CURSOR *cursor,
				  SMDB_DBENT *key,
				  SMDB_DBENT *data,
				  unsigned int flags));



struct cursor_struct
{
	db_cursor_close_func	smdbc_close;
	db_cursor_del_func	smdbc_del;
	db_cursor_get_func	smdbc_get;
	db_cursor_put_func	smdbc_put;
	void			*smdbc_impl;
};


struct database_params_struct
{
	unsigned int	smdbp_num_elements;
	unsigned int	smdbp_cache_size;
	bool		smdbp_allow_dup;
};

typedef struct database_params_struct SMDB_DBPARAMS;

struct database_user_struct
{
	uid_t	smdbu_id;
	gid_t	smdbu_group_id;
	char	smdbu_name[SMDB_MAX_USER_NAME_LEN];
};

typedef struct database_user_struct SMDB_USER_INFO;

struct entry_struct
{
	void	*data;
	size_t	size;
};

typedef char *SMDB_DBTYPE;
typedef unsigned int SMDB_FLAG;

/*
**  These are types of databases.
*/

# define SMDB_TYPE_DEFAULT	NULL
# define SMDB_TYPE_DEFAULT_LEN	0
# define SMDB_TYPE_IMPL		"implicit"
# define SMDB_TYPE_IMPL_LEN	9
# define SMDB_TYPE_HASH		"hash"
# define SMDB_TYPE_HASH_LEN	5
# define SMDB_TYPE_BTREE	"btree"
# define SMDB_TYPE_BTREE_LEN	6
# define SMDB_TYPE_NDBM		"dbm"
# define SMDB_TYPE_NDBM_LEN	4
# define SMDB_TYPE_CDB		"cdb"
# define SMDB_TYPE_CDB_LEN	4

# define SMDB_IS_TYPE_HASH(type)	(strncmp(type, SMDB_TYPE_HASH, SMDB_TYPE_HASH_LEN) == 0)
# define SMDB_IS_TYPE_BTREE(type)	(strncmp(type, SMDB_TYPE_BTREE, SMDB_TYPE_BTREE_LEN) == 0)
# define SMDB_IS_TYPE_NDBM(type)	(strncmp(type, SMDB_TYPE_NDBM, SMDB_TYPE_NDBM_LEN) == 0)
# define SMDB_IS_TYPE_CDB(type)	(strncmp(type, SMDB_TYPE_CDB, SMDB_TYPE_CDB_LEN) == 0)

# define SMDB_IS_TYPE_DEFAULT(t) (((t) == SMDB_TYPE_DEFAULT) \
	|| (strncmp(type, SMDB_TYPE_IMPL, SMDB_TYPE_IMPL_LEN) == 0)	\
	)

# if CDB >= 2
#  define SMCDB_FILE_EXTENSION "db"
# else
#  define SMCDB_FILE_EXTENSION "cdb"
# endif
# define SMDB1_FILE_EXTENSION "db"
# define SMDB2_FILE_EXTENSION "db"
# define SMNDB_DIR_FILE_EXTENSION "dir"

/*
**  These are flags
*/

/* Flags for put */
# define SMDBF_NO_OVERWRITE	0x00000001

typedef int (smdb_open_func) __P((SMDB_DATABASE **, char *, int, int, long, SMDB_DBTYPE, SMDB_USER_INFO *, SMDB_DBPARAMS *));

extern SMDB_DATABASE	*smdb_malloc_database __P((void));
extern void		smdb_free_database __P((SMDB_DATABASE *));
extern smdb_open_func	smdb_open_database;
# if NEWDB
extern smdb_open_func	smdb_db_open;
# else
#  define smdb_db_open 	NULL
# endif
# if NDBM
extern smdb_open_func	smdb_ndbm_open;
# else
#  define smdb_ndbm_open 	NULL
# endif
extern int		smdb_add_extension __P((char *, int, char *, char *));
extern int		smdb_setup_file __P((char *, char *, int, long,
					     SMDB_USER_INFO *, struct stat *));
extern int		smdb_lock_file __P((int *, char *, int, long, char *));
extern int		smdb_unlock_file __P((int));
extern int		smdb_filechanged __P((char *, char *, int,
					      struct stat *));
extern void		smdb_print_available_types __P((bool));
extern bool		smdb_is_db_type __P((const char *));
extern char		*smdb_db_definition __P((SMDB_DBTYPE));
extern int		smdb_lock_map __P((SMDB_DATABASE *, int));
extern int		smdb_unlock_map __P((SMDB_DATABASE *));

# if CDB
extern smdb_open_func	smdb_cdb_open;
# else
#  define smdb_cdb_open 	NULL
# endif
#endif /* ! _SMDB_H_ */